This invention relates generally to an optical serial link for exchanging data between two or more terminals.
The Infini-Band Specification includes a link specification that describes the behavior of a link and specifies the link level operations of devices attached to an Infini-Band fabric. See Infini-Band Specification, available from the Infini-Band Trade Association, 5440 Southwest Westgate Drive, Suite 217, Portland, Oreg. 97221 (Rev. 0.9, 2000). The Infini-Band architecture interfaces to the external world from a host channel adapter (HCA). For example, the HCA may provide communication between the fabric services and one or more central processing units which may, for example provide an Internet server function as one example. The HCA may be linked via a switch to a plurality of input/output ports. Generally, the HCA supports a link with a very high data rate.
An Infini-Band link is bi-directional communication pathway between two connect points within the switching fabric. Conventionally, the link may be formed of a copper cable. A short haul copper interconnect may have a bit rate of 2.5 gigabits per second.
One limitation of a copper link is that its bandwidth does not scale well with additional links. Electrical. interconnects on copper also face a daunting challenge in electromagnetic interference mitigation at very high data rates. This may also raise safety concerns due to increased radiation hazards.
Thus, there is a need for better techniques for implementing optical serial links at very high data rates.